JP2001075843A - Data management system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a technology for efficiently managing frequently used data and data that are not used so much. SOLUTION: This system is provided with a fast accessible high speed storage medium 14, a low speed storage medium 15 whose access speed is slower than that of the high speed storage medium and a managing means 11 for transferring design data that is not used, e.g. for three or more months among data existing in the high speed storage medium from the high speed storage medium to the low speed storage medium, and improves the use efficiency of a file server by preventing the storage capacity of the high speed storage medium from being pressed by the design data whose use frequency is low.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a data management technique, for example, a technique effective when applied to a local area network system.

[0002]

2. Description of the Related Art Local area networks (LANs)
Is a data communication system that allows a large number of independent devices to directly communicate with each other within an appropriate distance through a physical transmission line having an appropriate data transfer. According to this, devices such as workstations distributed on the same floor or in the same building are connected by a transmission medium such as a cable, and a facility network can be constructed as a corporate communication network.

[0003] With the enlargement and systematization of LSI,
The amount of LSI design data is increasing, and a large-capacity storage medium is indispensable in LSI design. Further, since an LSI designer needs to share LSI design data, a disk (file server) that can be shared by a plurality of workstations is required.

[0004] The file server is accessed via a network. To access the file server without deteriorating the performance of the application program, a file server capable of high-speed access is required. Such a file server is usually backed up regularly to store important data.

As an example of a document describing a local area network, there is “Basic LAN Basics” issued by Ohm Co., Ltd. on August 10, 1995.

[0006]

A file server is accessed via a network. To access the file server without deteriorating the performance of the application program, a high-speed accessible file server is required. Moreover, since a large amount of LSI design data is generated,
There is a tendency for the storage capacity of the file server to be used up in a short period of time.

The inventors of the present invention have examined the file server in such a network. As a result, there are many design data (usually unused data for a long time) which are not usually used in LSI design data. It has been found that even if the data storage destination is a low-speed storage medium, the overall performance is not degraded. That is,
Frequently used data is stored on a high-speed accessible file server, and long-term unused data is stored on a large-capacity storage medium even if high-speed access is not possible. It is thought that it can be used well.

However, even if the data is actually unused, if the data is backed up, the last read date and time of the data is updated by reading for the backup. The inventor of the present application has found that it is difficult to detect unused data for a long period of time because the data is used every time a backup is performed.

An object of the present invention is to provide a technique for efficiently using the storage capacity of a file server.

The above and other objects and novel features of the present invention will become apparent from the description of the present specification and the accompanying drawings.

[0011]

The following is a brief description of an outline of a typical invention among the inventions disclosed in the present application.

That is, there are a first file server having a high-speed storage medium capable of high-speed access, a second file server having a low-speed storage medium having a lower access speed than the high-speed storage medium, and the high-speed storage medium. The data management system includes a management unit for moving data that is not used for a predetermined period among the data to the low-speed storage medium.

According to the above-described means, the management server moves data not used for a predetermined period from the high-speed storage medium to the low-speed storage medium. As a result, the storage capacity of the high-speed storage medium is not squeezed by the design data that is not frequently used,
High-speed storage media that can be accessed at high speed can be used efficiently. In addition, since the design data that is used less frequently is stored in the low-speed storage medium, it can be used as needed. This achieves an improvement in the use efficiency of the file server.

A first file server having a high-speed storage medium capable of high-speed access, a second file server having a low-speed storage medium having an access speed lower than that of the high-speed storage medium, and a magnetic tape as a storage medium. A third file server for transferring, from the high-speed storage medium to the low-speed storage medium, data which is not used for a predetermined period among the data existing in the high-speed storage medium, and using the data for a predetermined period among the data existing in the low-speed storage medium; And a management means for moving the data not to be transferred to the magnetic tape device.

According to the above-mentioned means, the management server moves data that is not used for a predetermined period among the data existing in the high-speed storage medium from the high-speed storage medium to the low-speed storage medium. The design data that is not used for a predetermined period among the data existing in the low-speed storage medium is moved from the low-speed storage medium to the magnetic tape device. As a result, the storage capacity of the high-speed storage medium or the low-speed storage medium is not squeezed by the design data that is used less frequently, and the high-speed storage medium or the low-speed storage medium can be used efficiently. This achieves an improvement in the use efficiency of the file server.

At this time, the data moved from the first file server having the high-speed storage medium capable of high-speed access to the low-speed storage medium includes the high-speed access high-speed storage medium in consideration of subsequent file access. First
Symbolic links can be made from the file server.

Furthermore, even in the case where backup is frequently performed, in order to prevent data reading by the backup from being determined to be use of the data, the date and time when the last write was performed is indicated in the data management information. Including final writing date and time information, final reading date and time information indicating the date and time when the last reading was performed, and final special reading information indicating the date and time when the data was backed up to another storage medium,
It is preferable that the data detection by the management means is performed based on the last writing date and time information and the last reading information.

[0018]

FIG. 1 shows a local area network system to which a data management system according to the present invention is applied.

The local area network system shown in FIG. 1 is not particularly limited, but includes a plurality of designer workstations 10-1, 10-2, 10-3,...
0-n, the management server 11, the file server 20,
21 and 22 are connected to each other by a transmission medium 13 such as a communication cable so that data can be exchanged with each other.

Workstation 10-1 for designer
.., 10-n incorporate almost all the functions of the conventional design automation program, and are used as personal computer systems having a sophisticated user interface, and are used for designing LSIs. I do. The LSI designer can work interactively from specification determination to manufacturing without interruption by using the designer workstation. Errors in the design are immediately discovered by a design rule inspection program or simulation and can be corrected on the spot. Since the corrected result can be obtained immediately, high quality LS
I design becomes possible. In such LSI design,
Many design data supplied from the file servers 20 to 22 are referred to.

The file servers 20 to 22 have a plurality of designer workstations 10-1, 10-2, 1
Design data shared by 0-3,..., 10-n is stored.

The first file server 20 includes a high-speed storage medium 14 which can be accessed at a high speed, and a server workstation 17 coupled thereto. Although not particularly limited, the high-speed storage medium 14 is a magnetic disk device.

The second file server 21 includes a low-speed storage medium 15 having a lower access speed than the high-speed storage medium 14 but having a larger storage capacity than the high-speed storage medium, and a server workstation 18 coupled thereto. Comprising. Although not particularly limited, the low-speed storage medium 15 is an optical disk device.

The third file server 22 includes the magnetic tape device 16 and a server workstation 19 coupled thereto.

As shown in FIG. 2, the design data stored in the high-speed storage medium 14 and the low-speed storage medium 15 includes, in addition to the data part (a), management information of the data part (a). Department is included. The management information section includes a last writing date / time information section (A), a last reading date / time information section (B), and a last special reading date / time information section (C). The date and time when the data section (a) was finally updated by the execution of the program P1 is recorded in the final write date / time information section (A). The date and time when the data section (a) was finally read out by the execution of the program P2 is recorded in the last read date / time information section (B). The date and time when the data section (a) was finally backed up by the execution of the backup program P3 is recorded in the last special read date and time information section (C). The backup destination is a magnetic tape device (not shown) provided for each of the first file server 20 and the second file server 21.

The management server 11 is an example of the management means in the present invention. In order to prevent the storage capacity of the high-speed storage medium 14 from being squeezed by design data that is not frequently used, the management server 11 stores data stored in the high-speed storage medium 14. Among them, data that has not been accessed for a predetermined period is detected and moved to the low-speed storage medium 15. Further, in order to prevent the storage capacity of the low-speed storage medium 15 from being squeezed by the design data that is not frequently used, data that is not accessed for a predetermined period is detected from the data existing in the low-speed storage medium 15 and is magnetically detected. Move to the tape device 16. Whether data has not been accessed for a predetermined period can be determined by checking management information for each data. That is, the management server 11 determines whether or not the data has been accessed for a predetermined period by checking the last writing date / time information section (A) and the last reading date / time information section (B). The reason why the final special reading date and time information section (C) is not referred to in this determination is that
This is because it is considered inappropriate to read data for backup as “use of data”. By not including reading of data for backup in “use of data”, it is possible to appropriately check the use state of data.

Next, the operation of the local area network system configured as described above will be described.

FIGS. 3 to 9 show the flow of long-term unused data detection and data movement.

The management server 11 detects design data to be moved by referring to the last writing date / time information section (A) and the last reading date / time information section (B) according to a predetermined data movement rule. Specifically, the use status of the design data d1, d2 currently stored in the high-speed storage medium 14 is grasped based on the last writing date / time information part (A) and the last reading date / time information part (B) for each data. Then, design data for which a predetermined period has elapsed without writing or reading is detected (FIG. 3). Although not particularly limited, the predetermined period is three months. Here, for convenience of description, it is assumed that three months have passed without writing or reading only for d2 among the design data d1 and d2.

The design data d2 that has not been written or read for three months or more is data that is infrequently used,
Since the presence of such data in the high-speed storage medium 14 puts pressure on the recording capacity of the high-speed storage medium 14, the management server 11 moves the data from the high-speed storage medium 14 to the low-speed storage medium 15. That is, the data d2 is copied from the high-speed storage medium 14 to the low-speed storage medium 15 (FIG. 4), and thereafter, the data d2 is deleted from the high-speed storage medium 14 (FIG. 5). Here, the design data moved from the high-speed storage medium 14 to the low-speed storage medium 15 is indicated by d2 '.

The data d2 deleted from the high-speed storage medium 14 is stored in the workstation 1 for the designer.
.. 10-n, a link file having the same name as the original design data is created. The data d2 'in the low-speed storage medium 15 is symbolically linked (FIG. 6). Here, the symbolic link is one of file links in UNIX, and is also called a soft link. According to this symbolic link, a link between different file systems (file servers) is made possible.

For example, the file name of the design data d2 moved from the high-speed storage medium 14 to the low-speed storage medium 15 is / shi
If the file name is saku / 00001.dat, a link file with the same name is created in the high-speed storage medium 14, and this / shisaku / 0000
The original data in the low-speed storage medium 15 is symbolically linked to 1.dat. To create a symbolic link, use ln
The command may be executed with the -s option added.
Creation of such a symbolic link is performed by the management server 11
Done by

The link file is merely information for displaying a file name or an icon, and has a size of several tens or hundreds of bytes or less. Therefore, the amount of information is extremely large as compared with the original design data. Few. Therefore, the storage capacity of the high-speed storage medium 14 is not squeezed by the existence of the link file.

With such symbolic links, designer workstations 10-1, 10-2, 10-
When the design data d2 in the high-speed storage medium 14 is accessed from any one of 3, 3,..., 10-n, since it is symbolically linked, the link source data of the link file in the high-speed storage medium 14 That is, the link source data d2 'in the low-speed storage medium 15 is read.

A link file having the same name as the file name of the design data d2 moved from the high-speed storage medium 14 to the low-speed storage medium 15 is created in the high-speed storage medium 14,
Since the original data in the low-speed storage medium 15 is symbolically linked to the link file, the design data to be accessed has already been moved to the low-speed storage medium 15 in the designer workstations 10-1 to 10-n. Even if it had been done, there was no need to be aware of that.

Further, the management server 11 sets the last write date / time information section (A) in accordance with a predetermined data movement rule.
The design data to be moved from the low-speed storage medium 15 to the magnetic tape device 16 is detected with reference to the last read date and time information section (B). Specifically, by referring to the usage status of each design data currently stored in the low-speed storage medium 15, that is, the last writing date / time information section (A) and last reading date / time information section (B) for each data. Then, design data for which a predetermined period has elapsed without writing or reading is detected (FIG. 7). Although not particularly limited, the predetermined period is six months. Here, for convenience of explanation, it is assumed that six months have elapsed without writing or reading of only d2 ′ in each design data.

The design data d2 ', which is not written or read for more than six months, is data that is used very infrequently. The existence of such data in the low-speed storage medium 15 means that the recording capacity of the low-speed storage medium 15 is small. Therefore, the management server 11 uses the design data d
2 'is moved from the low-speed storage medium 15 to the magnetic tape device 16. That is, the design data d of the low-speed storage medium 15
2 ′ is copied to the magnetic tape device 16 (FIG. 8), and thereafter the design data d2 ′ is deleted from the low-speed storage medium 15 (FIG. 9). Here, the design data moved from the low-speed storage medium 15 to the magnetic tape device 16 is indicated by d2 ″.
Is deleted, and the file for the link that is the symbolic link destination of the data is accessed,
An error occurs when "File does not exist". By this error, it is possible to know that the desired design data has already been moved to the magnetic tape device 16.

According to the above example, the following functions and effects can be obtained.

(1) High-speed storage medium 1 capable of high-speed access
4 and a low-speed storage medium 15 having an access speed lower than that of the high-speed storage medium 14.
The design data that has not been used for three months or more among the data existing in the storage medium is moved from the high-speed storage medium 14 to the low-speed storage medium 15. As a result, the storage capacity of the high-speed storage medium 14 is not limited by the design data that is used less frequently, and the high-speed storage medium 14 that can be accessed at high speed can be used efficiently. In addition, since the design data that is used less frequently is stored in the low-speed storage medium 15,
It can be used as needed. The low-speed storage medium 15 has a lower access speed than the high-speed storage medium 14, but the design data stored therein is less frequently used, so that the overall performance is not reduced.

(2) Among the data existing in the low-speed storage medium 15, design data that has not been used for six months or more is moved from the low-speed storage medium 15 to the magnetic tape device 16. As a result, the storage capacity of the low-speed storage medium 15 is not limited by the design data that is used less frequently, and the low-speed storage medium 15 can be used efficiently. In addition, since the design data that has been used less frequently has been moved to the magnetic tape device 16, it can be used by returning it to the low-speed storage medium 15 as necessary.

(3) The design data moved from the high-speed storage medium 14 to the low-speed storage medium 15 is symbolically linked from the first file server 20, and the design data is transferred to the designer workstations 10-1 to 10-10. -N
Is designed to be read from the low-speed storage medium 15 when the first file server 20 is accessed from the first file server 20, the designer's workstations 10-1 to 10-n receive the desired design data. It is not necessary to be aware whether the design data of the high-speed storage medium 14 or the low-speed storage medium 15 exists.

(4) Further, the data management information includes final writing date and time information indicating the date and time when the last writing was performed, final reading date and time information indicating the date and time when the last reading was performed, and a backup to another storage medium. The last special read information indicating the date and time when the data is included is included, and the detection of unused data for a long time is performed based on the last write date and time information and the last read information. Therefore, even when backup is frequently performed, The data read by the backup is not determined to be the use of the data, and the data management can be performed accurately.

Although the invention made by the present inventor has been specifically described above, the present invention is not limited to this, and it goes without saying that various modifications can be made without departing from the gist of the invention.

For example, in the above example, the data management information includes final writing date and time information indicating the date and time when the last writing was performed, and final reading date and time information indicating the date and time when the last reading was performed. By performing based on the last writing date and time information and the last special reading information, including the last reading information indicating the backup date and time, the data backup is excluded from the use of the data in the data management by the management server 11. However, the recording of the last special read information indicating the backup date and time can be omitted on the assumption that the last read date and time information is not updated by the backup date and time. Thereby, even when the backup is frequently performed, the data read by the backup is not determined to be the use of the data, and the data management can be performed accurately.

In the above description, the invention made mainly by the inventor has been described in the field of LSIs which have been used in the background.
Although a case has been described where the present invention is applied to a data management system for sharing design data, the present invention is not limited to this, and can be widely applied to a data management system for sharing various data.

The present invention can be applied on condition that data is transmitted at least via a transmission medium.

[0047]

The effects obtained by typical ones of the inventions disclosed in the present application will be briefly described as follows.

That is, a high-speed storage medium that can be accessed at a high speed and a low-speed storage medium whose access speed is slower than the high-speed storage medium are provided, and design data that is not used for a predetermined period among data existing in the high-speed storage medium is provided. But,
Since the high-speed storage medium is moved from the high-speed storage medium to the low-speed storage medium, the storage capacity of the high-speed storage medium that can be accessed at high speed by the design data that is used less frequently is not squeezed, and the high-speed storage medium can be used efficiently. it can. In addition, since the design data that is used less frequently is stored in the low-speed storage medium, it can be used as needed. The access speed of the low-speed storage medium is lower than that of the high-speed storage medium, but the design data stored therein is used less frequently, so that the overall performance is not reduced.

Since the design data which is not used for a predetermined period among the data existing in the low-speed storage medium is moved from the low-speed storage medium to the magnetic tape device, the storage capacity of the low-speed storage medium is reduced by the design data which is used less frequently. Is not compressed, and the low-speed storage medium can be used efficiently. Since the design data that is used less frequently is moved to the magnetic tape device, it can be used if necessary.

The design data moved from the high-speed storage medium to the low-speed storage medium is symbolically linked from the first file server, and the design data is accessed from the designer workstation to the first file server. Since the design data is read from the low-speed storage medium, the designer's workstation is conscious of whether the desired design data exists on the high-speed storage medium or the low-speed storage medium. Don't do it.

Further, the data management information includes final writing date and time information indicating the date and time when the last writing was performed, final reading date and time information indicating the date and time when the last reading was performed, and date and time when the data was backed up to another storage medium. Is included, and the detection of unused data for a long period of time is performed based on the last write date and time information and the last read information. Data reading is no longer determined to be using the data,
The above data management can be performed accurately.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration example of a local area network system to which a data management system according to the present invention is applied.

FIG. 2 is an explanatory diagram of data management in the local area network system.

FIG. 3 is an explanatory diagram of detection of long-term unused data in the local area network system.

FIG. 4 is an explanatory diagram of copying of long-term unused data in the local area network system.

FIG. 5 is an explanatory diagram of deleting long-term unused data in the local area network system.

FIG. 6 is an explanatory diagram of a symbolic link of long-term unused data in the local area network system.

FIG. 7 is a diagram illustrating detection of long-term unused data in the local area network system.

FIG. 8 is a diagram illustrating copying of long-term unused data in the local area network system.

FIG. 9 is an explanatory diagram of deleting long-term unused data in the local area network system.

[Explanation of symbols]

 10-1 to 10-n Designer's workstation 11 Management server 13 Transmission medium 14 High-speed storage medium 15 Low-speed storage medium 16 Magnetic tape device 20 First file server 21 Second file server 22 Third file server

Claims (5)

[Claims] 1. A first file server having a high-speed storage medium capable of high-speed access, a second file server having a low-speed storage medium having a lower access speed than the high-speed storage medium, and the high-speed storage medium. Management means for moving data that has not been used for a predetermined period of time to the low-speed storage medium among the data. 2. A first file server having a high-speed storage medium capable of high-speed access, a second file server having a low-speed storage medium having an access speed lower than that of the high-speed storage medium, and a magnetic tape as a storage medium. A third file server for transferring, from the high-speed storage medium to the low-speed storage medium, data which is not used for a predetermined period among the data existing in the high-speed storage medium, and using the data for a predetermined period among the data existing in the low-speed storage medium; Management means for moving data not to be transferred to the magnetic tape device. 3. The data management system according to claim 1, wherein the data moved from the high-speed storage medium to the low-speed storage medium is symbolically linked from the first file server. 4. The data management system according to claim 1, wherein said management means includes detection means for detecting data which has not been accessed for a predetermined period based on management information of the data. 5. The management information includes final writing date and time information indicating the date and time when the last writing was performed, final reading date and time information indicating the date and time when the last reading was performed, and date and time when the data was backed up to another storage medium. 5. The data management system according to claim 4, further comprising final special read information indicating the last write date / time information and last read information.